DRV8847: how to reduce undershoot & overshoot at turn on & off

Hi Allan,

Please give me a couple days to look into this. I'll get back to you when I know more. 

Best,

David

Hi Allan,

Bulk capacitance is used to smooth out any large variations in motor current. From schematics you included above there are 4 capacitors (C14, C15, C18, C20). From the symbols it looks like they could be all ceramic caps, and some are bypass for filtering. How much total bulk capacitance are you implementing? We generally recommend ceramic local bypass capacitors with low ESR to reduce noise on external low voltage power supplies. If possible, maybe increasing bypass capacitors or placing them closer to the pin would help to reduce noise. 

For more information on bulk capacitor sizing please see the following app note:

Bulk Capacitor Sizing for DC Motor Drive Applications 

Best,

David